Generation and Wavelength Control of Resonant Luminescence from Silicon Photonic Crystal Microcavities with Ge Dots

Abstract

Ge self-assembled quantum dots were embedded into two-dimensional photonic crystal microcavities fabricated on silicon-on-insulator substrates by gas-source molecular beam epitaxy (GS-MBE), electron beam lithography, and reactive ion etching (RIE). Light-emission characteristics of Ge quantum dots in the microcavities were characterized by room-temperature microphotoluminescence. Multiple sharp resonant luminescent peaks with quality factors of up to 600, corresponding to the resonant modes supported by the cavity, were observed in the emission range of Ge quantum dots. Control of the wavelengths of the photoluminescence peaks over a wide range from 1.3 to 1.6 µm was demonstrated by adjusting the lattice constant of the photonic crystals. The results show that embedding Ge dots into optical microcavities is a possible candidate for silicon-based light emitting devices.